Every CVE Search/ Get API key

CVE-2023-27581

github-slug-action vulnerable to arbitrary code execution

8.8 HighFix available

github-slug-action is a GitHub Action to expose slug value of GitHub environment variables inside of one's GitHub workflow. Starting in version 4.0.0and prior to version 4.4.1, this action uses thegithub.head_ref` parameter in an insecure way. This vulnerability can be triggered by any user on GitHub on any workflow using the action on pull requests. They just need to create a pull request with a branch name, which can contain the attack payload. This can be used to execute code on the GitHub runners and to exfiltrate any secrets one uses in the CI pipeline. A patched action is available in version 4.4.1. No workaround is available.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
Low
User interaction
None

What an attacker can affect

Confidentiality
High
Integrity
High
Availability
High

Exploit likelihood

1.58%Up 1.5 points since Mar 14, 2023
90%50%10%1%

What each source reports

CVE List Score used 8.8

github-slug-action vulnerable to arbitrary code execution

github-slug-action is a GitHub Action to expose slug value of GitHub environment variables inside of one's GitHub workflow. Starting in version 4.0.0and prior to version 4.4.1, this action uses thegithub.head_ref` parameter in an insecure way. This vulnerability can be triggered by any user on GitHub on any workflow using the action on pull requests. They just need to create a pull request with a branch name, which can contain the attack payload. This can be used to execute code on the GitHub runners and to exfiltrate any secrets one uses in the CI pipeline. A patched action is available in version 4.4.1. No workaround is available.

Record
CVE-2023-27581
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-77
Updated
2026-11-02
EUVDEUVD-2023-0908 8.8

github-slug-action is a GitHub Action to expose slug value of GitHub environment variables inside of one's GitHub workflow. Starting in version 4.0.0and prior to version 4.4.1, this action uses thegithub.head_ref` parameter in an insecure way. This vulnerability can be triggered by any user on GitHub on any workflow using the action on pull requests. They just need to create a pull request with a branch name, which can contain the attack payload. This can be used to execute code on the GitHub runners and to exfiltrate any secrets one uses in the CI pipeline. A patched action is available in version 4.4.1. No workaround is available.

Record
EUVD-2023-0908
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02
GitHub AdvisoriesGHSA-6q4m-7476-932w 8.8

github-slug-action vulnerable to arbitrary code execution

Impact

This action uses the github.head_ref parameter in an insecure way.

This vulnerability can be triggered by any user on GitHub on any workflow using the action on pull requests. They just need to create a pull request with a branch name, which can contain the attack payload. (Note that first-time PR requests will not be run - but the attacker can submit a valid PR before submitting an invalid PR). This can be used to execute code on the GitHub runners (potentially use it for crypto-mining, and waste your resources) and to exfiltrate any secrets you use in the CI pipeline.

Patches

Pass the variable as an environment variable and then use the environment variable instead of substituting it directly.

Patched action is available on tag v4, tag v4.4.1, and any tag beyond.

Workarounds

No workaround is available if impacted, please upgrade the version

ℹ️ v3 and v4 are compatibles.

References

Here is a set of blog posts by Github's security team explaining this issue.

Thanks

Thanks to the team of researchers from Purdue University, who are working on finding vulnerabilities in CI/CD configurations of open-source software. Their tool detected this security vulnerability.

Record
GHSA-6q4m-7476-932w
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-77
Updated
2026-11-02
NVD 8.8

github-slug-action is a GitHub Action to expose slug value of GitHub environment variables inside of one's GitHub workflow. Starting in version 4.0.0and prior to version 4.4.1, this action uses thegithub.head_ref` parameter in an insecure way. This vulnerability can be triggered by any user on GitHub on any workflow using the action on pull requests. They just need to create a pull request with a branch name, which can contain the attack payload. This can be used to execute code on the GitHub runners and to exfiltrate any secrets one uses in the CI pipeline. A patched action is available in version 4.4.1. No workaround is available.

Record
CVE-2023-27581
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-77
Updated
2026-11-02
OSV 8.8

github-slug-action vulnerable to arbitrary code execution

github-slug-action is a GitHub Action to expose slug value of GitHub environment variables inside of one's GitHub workflow. Starting in version 4.0.0and prior to version 4.4.1, this action uses thegithub.head_ref` parameter in an insecure way. This vulnerability can be triggered by any user on GitHub on any workflow using the action on pull requests. They just need to create a pull request with a branch name, which can contain the attack payload. This can be used to execute code on the GitHub runners and to exfiltrate any secrets one uses in the CI pipeline. A patched action is available in version 4.4.1. No workaround is available.

Record
CVE-2023-27581
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-77
Updated
2026-11-02
OSVGHSA-6q4m-7476-932w 8.8

github-slug-action vulnerable to arbitrary code execution

Impact

This action uses the github.head_ref parameter in an insecure way.

This vulnerability can be triggered by any user on GitHub on any workflow using the action on pull requests. They just need to create a pull request with a branch name, which can contain the attack payload. (Note that first-time PR requests will not be run - but the attacker can submit a valid PR before submitting an invalid PR). This can be used to execute code on the GitHub runners (potentially use it for crypto-mining, and waste your resources) and to exfiltrate any secrets you use in the CI pipeline.

Patches

Pass the variable as an environment variable and then use the environment variable instead of substituting it directly.

Patched action is available on tag v4, tag v4.4.1, and any tag beyond.

Workarounds

No workaround is available if impacted, please upgrade the version

ℹ️ v3 and v4 are compatibles.

References

Here is a set of blog posts by Github's security team explaining this issue.

Thanks

Thanks to the team of researchers from Purdue University, who are working on finding vulnerabilities in CI/CD configurations of open-source software. Their tool detected this security vulnerability.

Record
GHSA-6q4m-7476-932w
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-77
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
rlespinasse/github-slug-action
GitHub Actions
4.0.0 up to 4.4.1
4.4.1

History

History
RecordedChangedSources
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2023-27581 is a high vulnerability (CVSS 8.8) in Github-slug-action Project Github-slug-action, published March 13, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.58%, the 75th percentile. Fixed in rlespinasse/github-slug-action 4.4.1.

References

MoveEnter Open